Some vehicles, such as rail vehicles, employ back-up models for operating parameters that are utilized to control vehicle operation in the event that a signal provided by a sensor, or the like, is corrupted or unavailable. Typically, a back-up model is generated by an on-board controller of a vehicle to enable the vehicle to continue operation based on the back-up model in the event of sensor failure.
In one example, operation of a rail vehicle is controlled based on barometric pressure that is indicated by a signal received from a barometric pressure sensor. If the barometric pressure sensor fails, a back-up model of barometric pressure is employed that uses an intake manifold air pressure measured during a last time that the rail vehicle was at idle, or defaults to a designated value for maximum engine protection. Neither of these back-up models provides operating parameter data that is indicative of current ambient environmental conditions, and thus is less accurate and dependable than signals provided from a healthy barometric pressure sensor. For example, the designated value of the back-up model significantly de-rates power output of the engine for protection purposes. Accordingly, operation of the rail vehicle based on the back-up model may be limited or less efficient relative to operation based on sensor signal data.